Question

android做客户端socket如何让点击按钮向服务器发送信息

Answer 1

使用基于TCP协议的Socket
一个客户端要发起一次通信，首先必须知道运行服务器端的主机IP地址。然后由网络基础设施利用目标地址，将客户端发送的信息传递到正确的主机上，在Java中，地址可以由一个字符串来定义，这个字符串可以使数字型的地址（比如192.168.1.1），也可以是主机名（example.com）。
而在android 4.0 之后系统以后就禁止在主线程中进行网络访问了，原因是：

主线程是负责UI的响应，如果在主线程进行网络访问，超过5秒的话就会引发强制关闭，所以这种耗时的操作不能放在主线程里。放在子线程里，而子线程里是不能对主线程的UI进行改变的，因此就引出了Handler,主线程里定义Handler,子线程里使用。
以下是一个android socket客户端的例子：
---------------------------------Java代码---------------------------------------
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.UnknownHostException;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class TCPSocketActivity extends Activity {

public static final String TAG = TCPSocketActivity.class.getSimpleName();

/* 服务器地址 */
private String host_ip = null;
/* 服务器端口 */
private int host_port = 0;

private Button btnConnect;
private Button btnSend;
private EditText editSend;
private EditText hostIP;
private EditText hostPort;
private Socket socket;
private PrintStream output;
private String buffer = "";
private Context context;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_socket_test);
context = this;
initView();

btnConnect.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
host_ip = hostIP.getText().toString();
host_port = Integer.parseInt(hostPort.getText().toString());
new Thread(new ConnectThread()).start();
}
});

btnSend.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
new Thread(new SendThread(editSend.getText().toString())).start();
}
});
}

private void toastText(String message) {
Toast.makeText(context, message, Toast.LENGTH_LONG).show();
}

public void handleException(Exception e, String prefix) {
e.printStackTrace();
toastText(prefix + e.toString());
}

public void initView() {
btnConnect = (Button) findViewById(R.id.btnConnect);
btnSend = (Button) findViewById(R.id.btnSend);
editSend = (EditText) findViewById(R.id.sendMsg);
hostIP = (EditText) findViewById(R.id.hostIP);
hostPort = (EditText) findViewById(R.id.hostPort);
}

private void closeSocket() {
try {
output.close();
socket.close();
} catch (IOException e) {
handleException(e, "close exception: ");
}
}

Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if (0x123 == msg.what) {
toastText("连接成功！");
}
}
};

/* 连接socket线程 */
public class ConnectThread implements Runnable {
@Override
public void run() {
// TODO Auto-generated method stub
Message msg = Message.obtain();
try {
if (null == socket || socket.isClosed()) {
socket = new Socket();
socket.connect(new InetSocketAddress(host_ip,host_port),5000);
output = new PrintStream(socket.getOutputStream(), true,
"utf-8");
}
msg.what = 0x123;
handler.sendMessage(msg);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

/*发送信息线程*/
public class SendThread implements Runnable {

String msg;

public SendThread(String msg) {
super();
this.msg = msg;
}

@Override
public void run() {
// TODO Auto-generated method stub
try {
output.print(msg);
} catch (Exception e) {
e.printStackTrace();
}
closeSocket();
}

}

public class SocketThread implements Runnable {
public String txt1;

public SocketThread(String txt1) {
super();
this.txt1 = txt1;
}

@Override
public void run() {
// TODO Auto-generated method stub
Message msg = Message.obtain();
try {
/* 连接服务器 并设置连接超时为5秒 */
if (socket.isClosed() || null == socket) {
socket = new Socket();
socket.connect(new InetSocketAddress(host_ip,host_port),5000);
}
// 获取输入输出流
PrintStream ou = new PrintStream(socket.getOutputStream(),
true, "UTF-8");
BufferedReader bff = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
// 读取发来服务器信息
String line = null;
buffer = "";
while ((line = bff.readLine()) != null) {
buffer = line + buffer;
}

// 向服务器发送信息
ou.print(txt1);
ou.flush();
// 关闭各种输入输出流
bff.close();
ou.close();
socket.close();
msg.what = 0x123;
handler.sendMessage(msg);
} catch (UnknownHostException e) {
} catch (IOException e) {
}
}
}
}
-----------------------------布局文件activity_socket_test.xml--------------------------------------
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@color/white"
android:orientation="vertical" >

<EditText
android:id="@+id/hostIP"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dip"
android:hint="服务器ip"
android:singleLine="true"
android:inputType="text" />

<EditText
android:id="@+id/hostPort"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dip"
android:hint="端口"
android:singleLine="true"
android:inputType="number" />

<Button
android:id="@+id/btnConnect"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal"
android:background="@drawable/style_btn_shape"
android:layout_margin="5dip"
android:text="@string/connect"
android:textColor="@color/white" />

<EditText
android:id="@+id/sendMsg"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dip"
android:hint="需要发送的内容"
android:inputType="text" />

<Button
android:id="@+id/btnSend"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dip"
android:background="@drawable/style_btn_shape"
android:layout_gravity="center_vertical|center_horizontal"
android:text="@string/send"
android:textColor="@color/white" />

</LinearLayout>
-------------------------样式文件style_btn_shape.xml----------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<!-- 填充的颜色 -->
<solid android:color="#0465b2" />
<!-- 设置按钮的四个角为弧形 -->
<!-- android:radius 弧形的半径 -->
<corners android:radius="15dip" />

<!-- padding：Button里面的文字与Button边界的间隔 -->
<padding
android:left="10dp"
android:top="10dp"
android:right="10dp"
android:bottom="10dp"
/>
</shape>
------------------------------END---------------------------------------

Answer 2

和普通java网络socket无异。差别是，在处理网络的耗时时，为了防止网络阻塞带来的ui无响应，记得另起线程就行。同时利用handle，将处理的结果在UI线程进行更新。